This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).

Due to personal reasons, I left the research group. In accordance with the regulations of the funding institution, Xiamen Health Administration, China, I hereby declare a withdrawal of my signature, Zhi-Jun Zhang, from this paper. Authors to whom correspondence should be addressed are therefore; E-Mails:
Zhouzhibin74@163.com (Z.-B.Z.);
nioujianp@yahoo.com.cn (J.-P.N.); Tel.: +86-25-83272024 (Z.-B.Z.); +86-519-6159635 (J.-P.N.); Fax: +86-25-83272011 (Z.-B.Z.); +86-519-6068389 (J.-P.N.).